Thin postcentral gyrus sign

The thin postcentral gyrus sign is an anatomic landmark useful for identifying the central sulcus on cross-sectional imaging.

The anteroposterior dimension of the postcentral gyrus surface is less than that of the precentral gyrus surface, as seen in the axial or sagittal planes. Identifying two parallel gyri of differential thickness helps to localize the central sulcus, which lies between these two gyri.